Might have a reason the travel to Denver early in December and if things work out with this customer I would bring my ski stuff and tag on some days at Vail. Validates that the Epic Pass entices people to try and get there more frequently. A couple of years ago I skied Vail in early December and thought it was pretty decent actually. I wouldn't expect the back to be open yet and I know the amount and quality of the snow is going to depend on the weather, but with all that in mind are the prospects this early in the season for most of the front to be open and skiable decent?
I'm a flat lander from Pa. so skiing the Mid Mountain Express all day and those runs would be worth it to me. Doesn't Riva have snow making on it